Method and apparatus for straightening wire from a coil



J. GREVEN July 12, 1966 5 Sheets-Sheet 1 1 Filed Oct. 19.

IN VEN TOR J. GREVEN July 12, 1966 METHOD AND APPARATUS FOR STRAIGHTENING WIRE FROM A COIL 5 Sheets-Sheet 2 Filed 00*.- 19, 1962 INVE N TOP July 12, 1966 J. GREVEN 3,260,092

METHOD AND APPARATUS FOR STRAIGHTENING WIRE FROM A COIL Filed Oct. 19. 1962 5 Sheets-Sheet 5 INVENTOR United States Patent 3 260,092 METHOD AND APPA RATUS FOR STRAIGHTEN- ING WIRE FROM A COIL Johann Greven, Aachen, Germany, assignor to Schumag Schumacher Metallwerke G.m.b.H., Aachen, Germany, a German corporation Filed Oct. 19, 1962, Ser. No. 231,724

Claims priority, application Germany, Nov. 4, 1961,

Sch 30,513 14 Claims. (Cl. 72-161) My invention relates to a method and apparatus for unbending and straightening wires, especially those of considerable thickness, as they are being unwound from a coil, for instance, on a drum.

It has been proposed to straighten such wire between guide rollers. With the known straightening devices or prestraightening devices for wire pointing machines for example, a long piece of the wire at its commencement must first be straightened out by hand in order that it may be gripped by the transport or squeezing rollers. However, it is diflicult to lead the wire into the straightening device when the wire has a diameter of 15 mm. or more, for example 30 mm. An individual worker cannot manually bend the wire end from a drum to a sufficiently straight shape for passing the wire between the guide rollers, as the wire in such cases is much too stilf. Hence, the known apparatus requires pre-s traightening of the initial length of wire by a large number of workers when the diameter of the wire is great and, to avoid injury, the starting end must first be hammered straight on an anvil. The above-described method, required with the known apparatus, is complicated and time-consuming. Furthermore, since different coils of wire have their wire end differently clamped and bent to a greater or lesser extent, it is impossible to estimate, even approximately, the time needed for this preparatory work.

It is an object of my invention to afford unbending and straightening of coiled wire, especially wire of considerable thickness, without entailing the above-men tioned disadvantages. An object, more particularly, is to effect straightening of the wire by activity of a single operator without any difficulty.

According to one feature of my invention, the unbending and straightening of coiled wire, for instance from a drum, is effected .by holding the wire in a gripper near the wire end, and drawing the wire over the peripheral portion of a segment whose curvature is counter to that of the wire and which preferably has a substantially V-shaped groove along the wire-engaging periphery.

It has been found that it is much simpler to draw relatively strongly thick wires over such a wire bending segment with counter curvature than to lead the wires directly between the rollers of a straightening apparatus. With a suitable counter curvature of the bending segment the wire, due to its springiness, leaves the segment in approximately straight condition. If the bending segment has a V-shaped groove at its periphery, it is particularly easy to draw the opposing curved wire over the bending segment without the wire flipping over and away from the desired unbending direction. The gripping of the wire end can be elfected by means of gripping tongs or clamps, preferably with the aid of pulling machinery to readily furnish the necessary force. The gripping device is preferably constructed in such a manner that its jaws close more tightly upon the wire with increasing tractive force and thus pull the wire from the coil. Tests have shown that the degree of curvature of the wire before being straightened has no appreciable effect on the present method. Further, it is of no decisive importance whether or not the end of the wire is bent back upon itself. If this is not the case, the gripping 3,260,092 Patented July 12, 1966 device can be advantageously applied fair-1y near the end of the wire. If, however, the end forms a considerable angle with the remainder of the wire, the gripping device is applied at some distance from the end of the wire so that initially the angular end of the wire is not straightened out when the wire is drawn over the counter-curved bending segment. 'While, in principle, the invention can be employed with wires of any thickness, it is of particular significance for wires of great thickness, for example having a diameter of 15 mm., or 30 mm., or more.

According to another, preferred feature of my invenw tion, the wire after having 'been drawn over the wirebending segment is additionally led between straightening rollers in the manner known as such. However, since the wire is already extensively straightened by passing over the segment, it can now more easily be passed between the following rollers of an additional straightening device, now only called upon to elfect a minor, final correction in shape. 1

A further development of the method according to the invention is that for straightening out a bent-over wire end, the wire is first gripped at a location spaced from the sharply bent end and is then passed over the wirebending segment for a short distance in the normal working direction, thus straightening a corresponding portion of the wire with the exception of the end; then the gripper is removed from the wire and the wire is moved in the reverse direction so that now the wire end is passed between straightening rollers and is also straightened, whereafter the straightening of more of the wire is re-' sumed in the normal pulling direction.

According to another feature of my invention, I provide apparatus for carrying out the above-described method, comprising a wire-bending segment having a V: shaped groove at its periphery, a gripper device for pulling the wire off a coil on a reel or drum, and coilunwinding machinery by means of which the gripper device can be operated without coming into contact with the bending segment when pulling the wire over the seg ment.

According to a more specific feature, such a coilwinding machine has a strong pull lever which is driven by a motor or hydraulic means and to whose end the grip: per device is attached, for example bya short chain. Preferably, the pull chain lever is disposed above the wire-bending segment so that the lever can move without it or the gripper device coming into contact with the seg-' ment when the wire is being held by the gripper device. It is also advantageous when the pull lever projects radial-1y outward beyond the segment, that is if the active length of the lever moves on a circle of greater diameter than that of the wire-bending segment.

According to still another feature of the invention, some of the above-mentioned straightening rollers can be swung out to facilitate initially inserting the wire. The swinging displacement can be produced, for example, by means of a knee-action lever transmission. During straightening operation the rollers are pressed against the wire by means of compressed air or hydraulic means, for example.

The apparatus may have a driven pair of pinch rollers situated between the wire-bending segment and the straightening rollers, such pinch rollers serving primarily to move the wire in the working direction or the reverse direction. If desired, one of the two pinch rollers can be made displaceable to facilitate insertion of the wire. For this purpose the displaceable straightening rollers and the displaceable pinch roller are preferably mounted on a common carrier which is displaceable as a unit.

In a modification of the apparatus, the wire-bending segment has a number of rollers distributed over its periphery, the rollers preferably having grooves of V-shaped cross section. This has the advantage that no friction occurs between the wire and the segment when the wire is being drawn through the apparatus. Further modifications of the apparatus include making the pull lever rotatable so that there is no idle time for the return of the lever.- Further, the drum or reel for the wire can be displaceably mounted on the straightening apparatus. For example, it can be arranged on a carriage. It may also be given the form of a rotatable multiple reel. In the latter case, the two parts of a two-stage reel can be arranged one above the other for example, the lower reel being rotatable, while the upper reel remains stationary. The chain connecting the gripper device to the draw lever may be given a variable active length.

For further describing the invention, reference will now be made to the accompanying drawings which illustrate embodiments diagrammatically and by way of example, and in which:

FIG. 1 is a perspective representation of a wirestraightening apparatus;

FIG. 2 is a perspective view of a gripping device which forms part of the apparatus shown in FIG. 1;

FIG. 3 is a plan view of a reel bearing a coil of wire with the gripper device of FIG. 2 clamped tothe wire;

FIG. 4 is a side view of the wire-straightening portion of the apparatus;

FIG. 5 is a plan view of the same straightening portion as shown in FIG. 4 but in open condition as contrasted to the closed or active condition shown in FIG. 4;

FIG. 6 is a plan view of part of another embodiment of the wire-straightening apparatus; and

FIG. 7 is a view of the wire-bending segment showing the position of the gripper device and the end of the wire in an apparatus corresponding to that of FIGS. 1-5.

Referring to FIGS. 1 to 5, the crude wire is wound on a reel 2 which is rotatable in both directions. A wirebending segment 3 is rigidly fastened immediately adjacent .the reel and is peripherally engageable by the wire as it is being unwound from the reel. The segment has a recess extending radially inwardly from the segment periphery. Located in the recess are two rollers 7 and 9 of the straightening device. Three coactive rollers 6, 8 and 10 of the straightening device are disposed on a carrier 27 which is movable relative to the housing 26 of the apparatus in the direction toward and away from the rollers 7 and 9. All of the rollers are rotatable in both directions. The movable carrier 27 is connected by pins and spacers 14 (FIG. 5), two parallel linking rods 12, 12 and a crank pin 13 (FIG. 4) to a kneeaction lever '11.

Wire-bending segment 3 preferably extends over about 60 or more. Trial and error have shown that this leads to a particularly smooth operation of the apparatus so that the required straightening of the wire is readily obtained.

The piston rod 16 of a cylinder 16' engages the other end of the lever 11, the cylinder 16 being pivotally mounted on the stationary housing 26 at the one end remote from piston rod 16 and being actuable by compressed air or oil. The straightening rollers are driven from a gear motor 23 through a drive shaft 23, a bevel gear 17, a pair of bevel gears 17' and a pair of spur gears 18. The drive for the straightening rollers can be reversed as desired so that the wire between the straightening rollers can be moved in both directions. The driving force supplied by motor 23 for the rollers is so rated that the rollers can not only straighten the wire but'also overcome the resistance of the counter curvature of the wire. The speed of this drive is preferably made the same as the speed of any fabricating machine or equipment which receives the wire from the coil' straightening apparatus. The carrier 27 with the straightening rollers 8 and 10 and the pinch roller 6 can be tilted about the gear center point M (FIG. 4).

The wire is drawn from the reel 1 by means of a gripper device 29 which is attached by a short length of chain 28 to a pull lever 20 (FIGS. 1, 3, 7) driven through gearing 21 (FIG. 1) from a motor 22. The gripper device 29 is constructed in the manner of Dutch tongs and can be applied to any desired part of the wire. The width of the gripper device is such that the gripper may pass into the region of the segment 3 up to about one-half of the angular opening 3 (FIG. 3), without the gripper device coming into contact with the segment.

The pull lever 20 is given such a length that the chain 28 and gripper device 29 do not extend exactly radially in the direction of the pulled-out end of the wire, but deviate a slight amount from the tangential direction, thus keeping the gripper device out of contact with the angular opening 3'.

When first applying the gripper device 29 to a coil of wire to be straightened, the gripper device 29 is passed in open condition over the arcuate part of the wire end stuck into the body of the coil, as shown in FIG. 3. Then the motor 22 is switched on and the pull lever 20 starts moving. The jaws of the gripper 29 seize the wire more and more tightly as the tractive force increases and pull the wire from the coil. The wire is thus positively drawn into the angled groove 3 where it receives a curvature in the opposite direction to the curvature which the wire had in the coil. This causes the wire to become approximately straight so that it comes between the opened guide rollers to bear against the rollers 7 and 9. The wire is then pulled out such a distance that the still bent end is located beyond the straightening rollers.

Now the cylinder 16 is actuated, whereby the straightening rollers on carrier 27 are pressed with great force against the stationary rollers 7 and 9. This causes the wire to bend. The motor 23 is then switched on so that the guide rollers move the wire back towards the coil. By this means the still bent end of the wire is also straightened. The motor is then reversed and the wire again drawn from the coil and straightened. Thereafter, a further amount of wire is drawn through forward with the coaction of the pinch rollers 6 and 8 up to the desired total length.

For straightening very sensitive material, the rigid structure of the unbending segment can be substituted by a number of correspondingly arranged V-profile rollers which rotate about their respective roller axes as the wire material is being drawn through the apparatus, so that no friction occurs between the material and the unbending section. Such V-profile rollers are shown at 4 in FIG. 6. They are revolvably mounted on a carrier segment 19 in a machine otherwise corresponding to FIGS. 1 to 5.

The above-described method of the invention is considerably easier to carry out than the known methods involving preparatory straightening of the wire end. The present method can be carried out by a single operator without any difiiculty. A further advantage of this method is that it makes it possible to effect uninterrupted further fabrication of the Wire on drawing benches, ramming machines, pointing machines, straightening and cutting machines, Wire-processing machines, and the like. An important use of the method is thus for straightening crude wire to be further processed in the manner indicated, and the method is applicable to coils of rolled or drawn wires, for example.

The above-described apparatus is advantageous in operation when the part of the guide rollers and, if necessary, one of the pinch rollers can be displaced sufficiently to permit passing between the rollers not only the wire to be straightened but also the gripper device. When thereafter the gripper, during pulling operation, has passed between the rollers, the displaceable rollers can be returned to their original positions so that the wire is now held between the rollers. In this manner, the drawing of the wire over the bending segment and the proper insertion into the straightening apparatus are effected in a single operation. This greatly simplifies using the apparatus. It is also advantageous when the straightening rollers, as shown, have a V-section like the segment 3. The provision of the linking chain serves to compensate for difierences in height caused by the fact that the gripper device is guided from above the segment and rollers. The V-shaped peripheral groove of the rollers then causes the wire to slide into the groove. In this manner, the wire is positively guided from above into the space between the stationary rollers and the displaceable rollers. Hence, the laborious insertion of the wire, required with the known apparatus, is eliminated.

I claim:

1. The method of unbending and straightening wire from a coil wherein the wire has a thickness rendering it incapable of being unbent by hand, which comprises first gripping the wire of the coil by a gripper device near the wire end at the entry to a path defined by a wire-bending segment having a curvature opposed to that of the wire, and pulling the gripper device through said path with the wire from the coil passing over the peripheral portion of said wire-bending segment.

2. The method of unbending and straightening wire from a coil wherein the wire has a thickness rendering it incapable of being unbent by hand, which comprises first gripping the wire of the coil by a gripper device in the proximity of the wire end at the entry to a path defined by a wire-bending segment having a curvature opposed to that of the curved wire coming from the wire coil, and pulling the gripper device through said path with the wire from the coil passing through, and toward the bottom of, a V-shaped peripheral groove of said wire-bending segment.

3. The method of unbending and straightening wire from a coil wherein the wire has a thickness rendering it incapable of being unbent by hand, which comprises first gripping the wire of the coil by a gripper device in the proximity of the wire end at the entry to a path defined by a wire-bending segment having a curvature opposed to that of the wire coming from the wire coil, pulling the gripper device through said path with the Wire from the coil passing through, and toward the bottom of, a V- shaped peripheral groove of said Wire-bending segment, and subsequently passing the wire from the segment through a set of straightening rollers.

4. The method of unbending and straightening a wire from a wire coil having a sharply bent end, which comprises first straightening a length of Wire exclusive of said bent end by first gripping the wire of the coil by a gripper device in the proximity of the wire end, pulling the wire from the coil through, and toward the bottom of, a V-shaped peripheral groove of a wire-bending segment having a peripheral curvature opposed to that of the curved Wire coming from the wire coil, and subsequently passing the length of wire from the segment through a set of straightening rollers, then removing the gripper device from the wire and moving the wire in the reverse direction until said bent end is straightened by said rollers.

5. The wire-straightening method according to claim 4, comprising the additional step of reverting to forward straightening according to claim 3 after said bent end is straightened.

6. Apparatus for unbending and straightening wire from a wire coil wherein the wire has a thickness rendering it incapable of being unbent by hand, comprising means for accommodating a coil of the wire, a wire-bending segment mounted near said accommodating means and having a peripheral portion engageable by wire coming therefrom, said segment having an inlet and an outlet, said peripheral portion having a curvature contrary to that of said wire, and Wire-pulling machinery having -a gripper device movable between said inlet and outlet and adapted to attach the wire to pull it over and against said peripheral portion of said segment so as to thereby unbend the wire.

7. In wire-straightening apparatus according to claim 6, said wire-bending segment having a V-groove along said peripheral portion for engaging the wire to be straightened.

8. Apparatus for unbending and straightening wire from a wire coil, comprising means for accommodating a coil of Wire, a wire-bending segment having a peripheral portion with a V-shaped groove engageable by the wire coming from the coil, said peripheral portion having a curvature contrary to that of said Wire, a wire-pulling machinery having a gripper device for attaching the wire to pull it over and against said peripheral portion of said segment so as to thereby unbend the wire, and a straightening-roller device rotatably mounted near said peripheral groove to receive Wire pre-straightened in the groove, said roller device having two sets of rollers of which one set is movable away from the other to facilitate inserting the wire.

9. A wire-straightening apparatus according to claim 8, comprising reversible drive means for driving said rollers.

10. In Wire-straightening apparatus according to claim 8, said roller device comprising a pair of pinch rollers and reversible drive means connected to said pinch rollers for moving the wire in respective forward and return directions, said pinch rollers being situated between said segment and the straightening rollers of said roller device.

11. In wire-straightening apparatus according to claim 10, said pinch rollers being displaceable to facilitate inserting the Wire.

12. In wire-straightening apparatus according to claim 6, said Wire-bending segment having its wire-engageable peripheral surface extend at least over an arc of about 13. In wire-straightening apparatus according to claim 6, said wire-bending segment comprising a number of individually rotatable rollers disposed in an arcuate row beside one another, said latter rollers forming jointly said peripheral portion of said segment.

14. In Wire-straightening apparatus according to claim 13, each of said individual rollers of said segment having a V-shaped peripheral groove, and said row of rollers extending over an arc of at least 60.

References Cited by the Examiner UNITED STATES PATENTS 191,100 5/1877 Braukman et a1 20522 2,087,010 7/1937 Wardle et al 153-54 2,321,878 6/1943 Tyrrell 15388 X 2,336,524 12/1943 Bannister 153--35 X 2,750,984 6/ 1956 Miller 15354 FOREIGN PATENTS 353,479 5/1922 Germany.

CHARLES W. LANHAM, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner.

R. D. GREFE, Assistant Examiner. 

1. THE METHOD OF UNBENDING AND STRAIGHTENING WIRE FROM A COIL WHEREIN THE WIRE HAS A THICKNESS RENDERING IT INCAPABLE OF BEING UNBENT BY HAND, WHICH COMPRISES FIRST GRIPPING THE WIRE OF THE COIL BY A GRIPPER DEVICE NEAR THE WIRE END AT THE ENTRY TO A PATH DEFINED BY A WIRE-BENDING SEGMENT HAVING A CURVATURE OPPOSED TO THAT OF THE WIRE, AND PULLING THE GRIPPER DEVICE THROUGH SAID PATH WITH THE WIRE FROM THE COIL PASSING OVER THE PERIPHERAL PORTION OF SAID WIRE-BENDING SEGMENT. 